Snooze wrote:
LED lamps have improved a lot in the past few years, but I don't think
they're bright enough yet. to light up a pond properly.

How does 105 Lumens sound? It's expensive, though. The 1W LEDs are
a whole lot cheaper, but they only put out 25 Lumens. Their brightest
offerning is a 18 LED board which puts out 450 Lumens - and it only
needs a piddling 1A @ 21V. ;-)

http://www.luxeonstar.com

There's some app notes and a landscaping design guide at
http://www.lumileds.com/solutions/solution.cfm?id=7

glen.